Surface enhanced Raman spectroscopy (SERS) is an ultra sensitive analytical technique. It is characterized by low background absorption for water, narrow line-widths, and fluorescence quenching, which are important for use as a probe for analysis of biological samples. The Raman signals of probes anchored onto gold or silver nanostructured surfaces may be enhanced by several orders of magnitude (typically 106 to 1014) because of strong surface plasmon resonance of the nanostructured surface. This signal enhancement has been the basis for chemical sensing applications at lower concentrations but better detection limits, as exemplified in DNA detection, cancer diagnosis, and cellular/intracellular molecules detection.
Over the last few decades, efforts have been made to develop probes for hydrogen (H2O2) based on chemiluminescence, fluorescence, and electrochemical techniques. However, SERS probes for H2O2 have not been reported to-date. H2O2 is a key oxygen metabolite with important physiological and pathological effects in living organisms. In addition to its role as a messenger in cellular signal transduction, an abnormal level of H2O2 leads to oxidative stress and damage events which are associated with aging, and severe pathologies, such as, cancer, Parkinson's, and Alzheimer's diseases. Furthermore, H2O2 is also involved in many environmental and industrial food processes.
In view of the above, there remains a need to develop a highly sensitive and selective method for detecting hydrogen peroxide.